CVE-2026-48736Network attack vectorHinoki check available

SSRF bypass via omitted IPv6 transition prefixes

Published Jul 14, 2026 · Updated Jul 14, 2026

SSRF in Symfony allows remote attackers to reach private IPv4 targets through crafted IPv6 transition-form URLs. IpUtils::checkIp6() compares IPv6 addresses only against PRIVATE_SUBNETS, whose omitted 6to4, Teredo, NAT64, and IPv4-compatible prefixes let embedded private IPv4 addresses pass as public. Reachability requires an application to pass attacker-supplied URLs to NoPrivateNetworkHttpClient and depends on deployed IPv6 routing; successful requests can read internal-service responses.

CVSS severity8.6
High
EPSS probability0.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

SSRF in Symfony allows remote attackers to reach private IPv4 targets through crafted IPv6 transition-form URLs. IpUtils::checkIp6() compares IPv6 addresses only against PRIVATE_SUBNETS, whose omitted 6to4, Teredo, NAT64, and IPv4-compatible prefixes let embedded private IPv4 addresses pass as public. Reachability requires an application to pass attacker-supplied URLs to NoPrivateNetworkHttpClient and depends on deployed IPv6 routing; successful requests can read internal-service responses.

The record

CVE
CVE-2026-48736
Published
Jul 14, 2026
Updated
Jul 14, 2026
Vendor
Symfony
Product
Symfony HttpClient
Classifications
CWE-184, CWE-918, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 5.4.0, < 5.4.53

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Symfony · Symfony HttpClientversion=>= 5.4.0, < 5.4.53
Symfony · Symfony HttpFoundationversion=>= 6.0.0-BETA1, < 6.4.41; version=>= 7.0.0-BETA1, < 7.4.13; version=>= 8.0.0-BETA1, < 8.0.13
Symfony · Symfonyversion=>= 5.4.0, < 5.4.53; version=>= 6.0.0-BETA1, < 6.4.41; version=>= 7.0.0-BETA1, < 7.4.13; version=>= 8.0.0-BETA1, < 8.0.13

Published CVSS scores

6.9GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N
8.6NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-184Incomplete List of Disallowed Inputs
CWE-918Server-Side Request Forgery (SSRF)
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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